It scared thousands of people out of the water, introduced Hollywood to the summer blockbuster and captured three Oscars.

Jaws looks fierce here but producer Richard Zanuck said the mechanical shark often wouldn't work during shooting.

Universal Studios

Yet Jaws, the filmmakers concede, was a success despite itself.

Mechanical failures, inclement weather and budget overruns nearly sank the story of a great white shark that terrorizes the fictional seaside town of Amity.

"Most days we were walking around with our heads hung low," says Richard Zanuck, one of the producers. "The shark wouldn't work. The weather was lousy. We knew we had a good story. We just didn't know if we'd ever get it out there."

Jaws— which made a then-record $260 million in 1975 and won Oscars for sound, music and editing — turns 30 this summer. An anniversary DVD is out today. The $23 two-disc set includes a two-hour documentary, deleted scenes, outtakes and a 60-page photo journal.

The back story to the film is part of its legend. During a sneak preview in Dallas, producers Zanuck, David Brown and other executives realized from audience shrieks that they had a bigger hit than they thought.

"We looked for the quietest place in the theater to talk, the bathroom," says Brown.

There, the filmmakers decided to open the movie in hundreds of theaters on the same day, June 20, 1975, instead of gradually opening on a handful of screens and letting it roll out slowly, as films did then.

Hollywood and fans are already celebrating the historic release. This month, more than 3,000 fans descended on Martha's Vineyard, where the film was shot, for Jaws Fest, the first of what organizers hope will be an annual gathering.

A Jaws video game hits shelves later this summer. Gamers will play the shark, which can attack boats, fend off killer whales and dine on unfortunate divers.

"It's astonishing to me that Jaws still has currency in the popular culture," says Peter Benchley, who wrote the novel. "But I think we love our monsters. We don't just fear our predators. We're transfixed by them. And this one is real."